/*
 * Copyright 2008-present MongoDB, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.mongodb.internal.inject;

import com.mongodb.annotations.Immutable;

import java.util.Optional;

@Immutable
public final class EmptyProvider<T> implements OptionalProvider<T> {
    private static final EmptyProvider<?> INSTANCE = new EmptyProvider<>();

    private EmptyProvider() {
    }

    /**
     * Returns {@link Optional#empty()}.
     */
    @Override
    public Optional<T> optional() {
        return Optional.empty();
    }

    @SuppressWarnings("unchecked")
    public static <T> EmptyProvider<T> instance() {
        return (EmptyProvider<T>) INSTANCE;
    }
}
